Tesla CEO Elon Musk told electric utility owners they shouldn’t fear that his battery systems will put them out of business — instead, they should buy them.

Most customers in the U.S. will use the Powerwall home system as a backup in the event of a failure, not as a primary source of electricity replacing utility sales, Musk said Monday at a gathering of utility executives in New Orleans. Plus, Musk said electric cars like the Tesla Model S will help triple demand for power in the coming decades. He sees less than a third of that served by distributed generation like the battery storage system and solar panels Tesla backs.

Musk unveiled a suite of batteries in April that he said would “fundamentally change the way the world uses energy.” The equipment allows businesses and homeowners to store power, reducing the need to rely on utility grids for electricity. Musk said the media has been confused about the role of the home battery pack, which wouldn’t be economic as a main supply source. He sees 80 to 90 percent of sales being in the larger Powerpack system, which could help utilities store power to reduce the need for expensive facilities that only run during times of peak demand.

While Tesla’s industrial battery team has been meeting with utility executives for more than two years, Monday’s appearance at the Edison Electric Institute conference marks the first time that Musk, 43, has spoken publicly to the industry. Musk, who also serves as chairman of San Mateo-based SolarCity, was questioned by Ted Craver, the CEO of California utility owner Edison International, which has signed a deal to use Tesla’s batteries with its solar installations.